Bad Astronomy: Misconceptions and Misuses Revealed, from ...

BAD ASTRONOMY GOES HOLLYWOOD 249
side, turning the plane. But note what is doing the pushing: air.
Need I say it? No air in space.
To make a turn in space, you need to fire a rocket in the opposite
direction that you want to turn. Need to escape to port? Thrust
starboard. Actually, banking makes the situation even worse: it presents
a broader target to a pursuing enemy. Keeping the wings level
means less ship to aim at. Speaking of which, why do so many
movies have spaceships with wings in the first place?
To be fair, I’ll note that banking has one advantage. When a
car makes a turn to the left, the passengers feel a force to the right.
That’s called the centripetal force, and it would work on a spaceship,
too. Extensive tests by the Air Force have shown that the
human body reacts poorly to high levels of acceleration. A seated
pilot accelerated upward experiences forces draining blood away
from the brain, blacking him out. If he’s accelerated downward,
blood is forced into the head, an unpleasant feeling as well. The best
way for the body to take a force is straight back, pushing the pilot
into his or her seat. So, if a pilot flying a spaceship banks during a
turn, the centripetal force is directed back, pushing the pilot harder
against the seat. Blacking out during a space battle is not such a
hot idea, so maybe there’s some truth to banking in space after all.
One other thing: if the spaceship has artificial gravity, then the
computer should be able to account for and counteract any centripetal
force. So if you see a movie in which Our Heroes have
gravity onboard and still bank, you know that you’re seeing more
bad astronomy.
4. . . . and dodges laser beams from the Dreaded Enemy . . .
If screenwriters have a hard time with the speed of sound,
imagine how difficult it must be for them to work with the speed
of light. Perhaps you’ve heard the phrase “300,000 kilometers
(186,000 miles) per second: not only a good idea, it’s THE LAW!”
They aren’t kidding. According to everything we understand about
physics today, nothing can travel faster than light. Now I accept
that someday, perhaps, we may find a way around that limit. No
one wants to do that more than astronomers: they would give up
their biggest grant to climb aboard a spaceship and zip around the